[ONPREM-1904] Add option to override orchestrator init container image (

#71)

* Add option to override orchestrator init container image

This can be used for hosting the image in a private registry, or air-gapped environment on CircleCI server.

* Add unit tests for orchestrator image configuration

* Add changelog entry and bump chart version

Grant list permissions for Pods and events [ONPREM-1643] (#66)

* Grant list permissions for Pods and events

* Add changelog entry and bump version for release

* Update README

Merge pull request #61 from CircleCI-Public/ONPREM-1297/only-trigger-…

…k8s-smoke-tests

Only trigger the Kubernetes smoke tests